class Post < ActiveRecord::Base
  
  # Associations
  belongs_to :forum, :counter_cache => true
  belongs_to :topic, :counter_cache => true, :touch => true 
  belongs_to :user, :class_name => "User", :counter_cache => true
  
  # Accessors
  attr_accessible :body
  
  # Validations
  validates :body, :presence => true
  validates :user, :presence => true
  
  # Default Scope
  default_scope :order => 'created_at ASC'
  
  # Scope to display only the last n posts. Used for "Recent Posts" display
  scope :recent, lambda {
    |c| reorder('created_at desc').limit(c)
  }
  
  # Callbacks
  before_save :topic_locked?
  
  # Methods
  private
    def topic_locked?
      if topic.locked?
        errors.add(:base, "That topic is locked")
        false
      end
    end
end